Cooker causes the house to plunge into darkness!

[TrafficCone]

hi there.

today i paid an obscene amount of money for an emergency electrician to wire in my new cooker in time for christmas. it apparently worked fine. however; when it gets up to temperature it trips the main house trip switch - though not the cooker circuit.

after paying a blood curdling amount i would rather not call an electrician again if its something i can sort myself. might it be the trip switch itself?

interestingly. the last time it tripped the switch - i turned off the oven and reset the trip switch. i then walked back to the kitchen and just turned the oven light on - and the house was plunged into darkness again. how can just turning the oven light on trip the switch?

any help is gratefully received. i will of cause be phoning the electricians in the morning

 

[JohnD]

I think the thing it is tripping is probably an RCD. What is written on the thing that trips?

It is not usual to connect cookers on the RCD side, if you have a split-load CU, because oven elements often have slight earth leakage.

Can you put up a photo of the consumer unit showing the devices inside (don't take the cover off).

What is the power rating (Amps or kW) of the cooker?

Have you phoned the electrician and complained?

Is the cooker new or used?

You say the lights go off too? Are you in a country area with an overhead supply and a whole-house RCD?

 

[TrafficCone]

hi john. thanks for the swift reply.

the switch that gets tripped is the main trip swich on the house fuse box. written under the switch is 'current operated earth leakage circuit breaker'.

sorry am a bit confused by whether you want a photo of the oven or the fuse box!?!

the instruction manual states the oven needs a 13amp fuse and is rated at 2250w - 2400w. having just read some more in the maual it states' the earthing wire must not be interrupted by the circuit breaker [if fitted directly to the mains]).

i should add at this point that the oven unit came with a conventional 3 pin plug - which the electrician removed to fit to the same box as the hob is wired into. (which is how the old cooker was wired in.) does it sound then if the electrician should have bypassed the earth pass the main trip switch? is this even possible?

the oven unit is brand new. and i will of cause phone the electrician first thing in the morning. oh- and no overhead power cabels here, i live in the middle of quite a large town.

thanks for you help.

 

[joe-90]

If the oven turns out to be faulty - does anyone know if removing the plug voids the warranty?

 

[TrafficCone]

i dont believe it would. the manual offers two ways of installing; with the plug or disposing of the plug and connecting directly to the mains.

 

[joe-90]

i dont believe it would. the manual offers two ways of installing; with the plug or disposing of the plug and connecting directly to the mains.

Yes, you are right.

 

[JohnD]

Welcome back.

It was a picture of the fuse box I wanted, to see how it is configured (it is more common not to put the lights through the RCD, only the sockets. the idea is that it is more dangerous to have all the lights go out sudddenly, especially if you are carrying something heavy, running downstairs, or up a ladder when a fault occurs.

You were very generous to pay an electrician to fit a cooker that comes with a 13A plug

I presume you also have a gas or fixed electric hob you can use. For tonight, leave the oven switched off at the wall switch (if there is one). Tomorrow get the electrician back. Also call the oven supplier and say it has an earth fault and is tripping your RCD. Perhaps they will send someone to look at it before the turkey needs to go in.

Are there any sockets at all in the house that still work after the RCD has tripped?

If you can post a pic of the consumer unit (fusebox) before then we may have some more wise advice for you.

there is a faint chance that the electrician has left a stray wire loose, but I think it is more likely the oven at fault (plus the inconvenient configuration of the CU)

p.s. have you still got your old cooker, or did it go in the skip?

 

[TrafficCone]

thanks for your help guys. i will post a pic of the fuse box in a liitle while. i'm off to get a takeaway. (not joking )

 

[mst]

gentlemen am i right in saying that the oven is supplyed "from the same box the hob is wired into" 30-32 amps????????????????

Not a good start is it.

Unless it was downrated at the board.....but was it?

Photos will tell.

 

[TrafficCone]

as promised. a pic of my fuse box.

 

[JohnD]

Gosh, you don't see many of them!

Bit of a problem here.

That CU has a single RCD that protects the whole house. I can't read the label. Does it say "30mA" or "0.03Amp" on it?

That is considered rather undesirable, because a fault on one circuit will mean that you lose all power on all circuits, including those which are not faulty.

Additionally, slight earth leakages from various appliances and various circuits, which are individually not significant, will add together and can be enough to trip the RCD. As you have a fairly old installation, this is the most likely cause. It is also possible that the RCD has got overssensitive with age, though I think this is fairly unlikely.

Best solution would be to have a new CU fitted with RCBOs per circuit

However you will probably not get that done by christmas.

Do you find the RCD trips from time to time (prior to the new cooker)?

I am trying to think if there is a better approach than removing or bypassing the RCD. As that model is obsolete I doubt there will be a 100mA RCD available to swap.

p.s. Is that the only consumer unit you have, or is there another one for an electric shower, outbuilding or anything?

p.p.s. Just remembered - occasionally ovens get a bit damp in storage which can lead to a bit of earth leakage. Do you have anything like a small heater or a wanderlamp that you can put in the oven to warm it up overnight?

 

[TrafficCone]

aaagghhh..

ok. it says 30mA trip. Never had any problems with it tripping before. Thanks for all you help. Back to microwave food for a while then.. yum

 

[Steve]

5 digit telephone number, lol. how olds that!

 

[ebee]

I`d like to know what you consider was an obscene amout to pay and what was the work actually done and what was the lead time.

The most likely cause is the cooker (faulty or damp).
If this turns out to be the case are you going to begrugde paying the electrician to come back?

 

[sm1thson]

gentlemen am i right in saying that the oven is supplyed "from the same box the hob is wired into" 30-32 amps????????????????

Not a good start is it.

Unless it was downrated at the board.....but was it?

Photos will tell.

hmm, i know we are trying to solve the problem not find more but i really think this needs addressing aswell! -can you post pictures of what the electrician has done!